str1 = "hello world "
str2 = 'hello world '
str3 = '''hello 
world '''
print(str1)
print(str2)
print(str3)
print('hel\'lo world')  # \'转义符
#\n换行符
print('123---{0}---{1}---{2}'.format(4,5,7))
str1 = 'hello'
print(f'123---{str1}')

for i in range(0,101,2):
    print("===========开始下载===========")
    if i == 100:
        print("下载完成")
    else:
        str4 = "*"*(i//2)+"."*((100-i)//2)
        print(f'{i}%[{str4}]')
        #print(f'{i}%','[',"*"*(i//2),"."*((100-i)//2),']')



